Sintering furnace



Jan. 13, 1942.

W. L. WROBLEWSKI S INTERING FURNACE Filed VMarch 29, 1941 3 Sheets-Sheet l QR MH..

Jn. 13, 1942. w. l.. WROBLEWSKIy 2,259,838 Y SINTERING FURNACE Filed March 29, 1941 '3 Sheets-Sheet 2 gill/111111111111111 Jan. 13, 1942. w. l.. wRoBLl-:wsKl

S INTERING FURNACE Filed Maron 29, 1941 s sheets-shea s n vom-1 to@ w k 10 L. M W

vof means for removing the patented Jan. 13, 1942 v UNITED STATES PATENT OFFICE 2,269,839 srN'rEmNG FURNACE Woodrow L. Wroblewski, Schenectady, N.

Application March 29, 1941, serial No. 385,939

3 Claims.

My invention relates to heating apparatus and more particularly to sintering furnaces.

One of the principal objects of my invention is to provide a sintering furnace assembly so constructed and arranged whereby the products to be sintered, for instance, magnets and the like, are progressively subjected to treatment by the furnace assembly to effect quantity production.

An important object of my invention is to provide a sintering furnace assembly` of the character described which' is simple .in construction, durable in use, eflicient in operation and economical in manufacture.`

With the above and other objects in view, as

. powder with the heating unit will 'hereinafter appear, the invention consists in the combination, and arrangement of parts hereinafter set forth and illustrated in the acwhich the several features of the invention and the' advantages attained thereby will be readily understood by those skilled in the art.

Referring to the drawings wherein like reference characters designate like parts throughout the several views:

Figure 1 is a side elevation, partly in section, of my sintering furnace assembly.

Figure 2 is a vertical sectional-view of the furnace.

Figure 3 is an end elevation of one of the boats.

Figure 4 is a sectional view taken on the line 4-4 of Figure 3.

Figure 5 is a sectional view taken on the line 5-5 of Figure 1.

Figure 6 is a side elevation of a modified form boats from the endless conveyor and positioning said boats onthe elevating means. 1

As illustrated in the drawings, I provide a hydrogen furnace 4 comprising a cylindriform shell or wall 5 .having secured within its ends a pair of end walls 6 and 1 respectively. The inner face of the wall 5 is equipped with asbestos material 8 constituting a seal. The end walls 6 and 1 are formed with central apertures in electric terminal connections I3 adapted to be which is connected to a source of electrical energy (not shown) for operating-the unit. c

The furnace contains aluminium oxide powder I4 (A1203) which is disposed about the casing 9, the latter serving to preclude contact of the I0 and to maintain the same within the furnace. Extending through the powder, the top of the wall 5 and the casing 9, are a pair of pipes I5 connected to a hydrogen supply pipe I6 whereby the interior 9 about the unit I0 is supplied with is in a cool or faces of the end walls, adjacent the apertures, have welded thereto flanges I1, while the' outer faces have secured thereto collars I8, the latter'having their inner margins maintaining the ends ofthe heating unit I8 within the casing 9.

Subjacent the furnace 4, the assembly is provided with an endless conveyor 20, the latter comprising a supporting frame 2| having upper horizontally extending end portions on which are 'rotatably mounted rollers 22 over which are of a tube belt 23 having upper and lower horizontal runs 24 and 25 respectively. Adjacent the end wall l of the furnace, the assembly is provided with a vertically disposed conduit 26, the latter formed on one side, interjacent its upper and lower ends, with a lower horizontal inlet branch 21 having its Aouter open end terminating adjacent the conveyor 20. The branch 21 is provided, interjacent its ends, with a vertically sliding gate valve 28, the latter the plunger 29 of a solenoid 39 whereby said valve 28 is operated to open and closed positions as trained an endless hereinafter set forth.

The conduit 26, subjacent its upper end and superjacent the branch 21, is provided with a horizontally 'sliding gate valve 3l of a similar construction as the valve 28 and said valve 3| is connected to the plunger 32 of a solenoid 33 whereby said valve is operated to open and closed positions as hereinafter set forth. The upper end of theconduit 26 is provided with an upper horizontal outlet branch 34 having an open end conto the inlet endA nected by means of a coupling 35 36 extending through said heating unit l0, the opposite end of said nected to an upper horizontal branch on the upper end of a vertical conduit 38 adjacent the wall 6 and of a similar construction as the conduit 26. The opposite end of the branch 34 is closed by extending therethrough one end of the plunger being aconnected to a wall 39 which has slidably rod 40 of a solenoid 4| for a purpose hereinafter walls 12. The outer end faces of the deten-ts 14 described.V incline upwardly and inwardly to provide cam As in the instance of the conduit 26, the consurfaces for engagement with depending hookduit Il is formed on one side, interjacent itsy uplike portions 16 formed on the outer ends of the rods 50 and 58 of the solenoids 5| and 60 respecbranch 42 having its open end terminating adjatively for a purpose hereinafter made apparent. cent the opposite end oi' the conveyor 20. The The outer end of the rod 58, adjacent the hookbranch 42 is provided, interjacent its ends, like portion 16. iS formed with a depending 1in T7 with a. vertically sliding gate valve 43 conhaving an inclined foce for engagement With' 2 nected to the plunger u of a s01enoid 45, 10 projection 18 carried on .the adjacent face of the while the conduit 3a, between the ranches wall of the conduit 26 whereby to effect raising 31 and 42 is provided with a. horizontally of the hook-like portion 16 to disengage the same sliding gate valve 46 connected to the plungfrom the detent 14 when said rod ls actuated to er 41 of a solenoid 45, said solenoids 45 and 48 retracted position Within the Solenoid 60 for o serving to operate their'gespeetive valves to open 15 purpose hereinafter made apparent. The bottom and closed positions as hereinafter set forth. The Wall 1| of each boat is provided with a convex `opposite end of the branch 31 is elosed by a lower face having a contour similar to the conwall 49 which has slidebly extending theretour of the tube 36, it being understood 'that the through the plunger rod 50 of a solenoid 5| for faces of the upper and lower branches of the a purpose hereinafter described, conduit lthe platforms and conveyor runs on The conduits z3 and :s are equipped, subjacent which the boats are moved are of a similar contheir lower Branches 21 and 42 respectively, with tour 8S that of the tube 36. hydraulic cylinders 52 in which are reciprocally In operation the Darts being in the D OSitiOnS spect to the upper and lower horizontal branches 3o noid 6 is operated to actuele its rod 58 to Droof 'the conduits for a. purpose hereinafter set jected position Within the branch 27 and effect forth. 'I'he cylinders 52, subjacent the pistons 53, locking engagement of the portion 16 with the have connected thereto pipes 56 whereby fluid detont 74 of the boat. whereupon. Said rod 58 iS may be `introduced into and discharged from the operated towards retracted position thereby movcylinders to eect raising and lowering of the 3o ing the boat onto the Platform 55 and didonpistons. gaging the portion 16 with the detent 14 through The walls of the conduits 26 and 38, oppositely the medium of the lip 11 and projection 73- disposed from the lower horizontal branches, When the boat is thus disposed onto the platends of piston rods 52 and 55 of solenoids 60 and 4o .55 is operated upwardly to position the boat Withhydrogen Supply pipes 62 whereby to supply the the platform 55, the valve 28 is actuated to closed conduits with hydrogen, it being understood that position by the solenoid and the valve 3| to the gate valves constitute locks and said conduits open Position' by the Solenoid 33. When the boat 53 containing liquid for cooling the branch and and centrally within the furnace 5 as illustrated products introduced therein, said branch con- 5o in dotted lines in nFigure 1. Upon movement stituting a cooling chamber for cooling products of the boat into the tube 36, the platform is introduced therein as hereinafter set forth. The actuated to its lower position by means of its branch 31, adjacent the tube 36, has connected piston 53 while the valve 3| is closed by the solethereto a hydrogen supply pipe 64 coacting with noid 33. When the products or 'magnets con-` the pipe 62 to maintain a supply of hydrogen 55tained on the boat have been sufficiently treated within the tube 36, it being `understood that it by the furnace, the solenoid 5|' is operated to In order that products, for instance. magnetg by the solenoid 5| towards retracted position to detents 14 extending upwardly between the sides 3| is' operated to reciprocate its rod 59 and thus defining said recesses and terminating an appreengage and move the boat out G1 the branch n ciable distance subjacent the upper ends of said onto the conveyor 2U for removal therefrom.

By continuously depositing boats upon the conveyor 20, and operating the parts in the foregoing described manner, it will be apparent that a plurality of the boats containing their products may be continuously and progressively operated through the foregoing described cycle of operation thus contributing to quantity production. It is to be understood that the various solenoids and pistons are to be operated in a predetermined timed relation and in a manner whereby the valves serve to maintain suflicient hydrogen within the tube 36. i

Y As illustrated in Figure 6 of. the drawings, the outer end of the rod 58 of the solenoid 60 may be equipped with a magnet 80 in lieu of its portion 16 and the boats provided with metallic end plate 8i for engagement with the magnet whereby when said magnet is energized and the rod 56 operated to retracted position the boat will be moved onto the platform 55 and released' from the rod 58 when the magnet is deenergized. Similarly, if desired, the outer end of the rod 50 of the solenoid 5I may be constructed in the same manner. A

While I have disclosed the valves 28, 3|, 43 and 46 and the boats 10 as being operated or moved by solenolds, it is to be understood that other operating means may be substituted 'in lieu thereof, for instance, hydraulic cylinder and piston assemblies. Furthermore, it is to be understood that should a process of sintering pressed material require hydrogen circulation, the hydrogen may be introduced, under a desired circulating pressure, into the tube 36 through the pipe 6I andvbe discharged from said tube at its opposite end into a dehydrator to remove water vapor from the hydrogen whereupon said hydrogen may be conveyed, under pressure, to the pipe 64 for recirculation through the tube. It will be apparent that when hydrogen is so circulated and thus utilized economy in operation is effected. If desired, the hydrogen may be introduced into one end of the heater unit and circulated through the spiral groove in which the heating element is disposed. When hydrogen is thus circulated it may be burnt at the other end of the unit or conveyed to a cooling coil, puried and recirculated thereby reducing hydrogen loss to a mini'- mum.

From. the foregoing, it will be apparent that my invention not only lends itself to quantity production in the sintering of products but also comprehends many advantages and desirable features not obtainable in other sintering apparatus, for instance, (a) simplicity of construction (f) automatically moving the material from the heating tube 36 into a cooling chamber; (g) and utilizing a substantially cylindrical heating tube whereby maximum strength is maintained at high temperatures.

Without further elaboration the foregoing will so fully explain the invention that others may, by applying current knowledge, readily adapt the same for use under variousl conditions of service. Moreover, it is not indispensable that all the features of the invention be used conjointly'since they may be employed advantageously in various combinations and ysub-combinations.

It is obvious that the invention is not conned to the herein described use therefor as it may be utilized for any purpose to which it is adaptable. It is therefore to be understood that the invention is not limited to the specific construction as illustrated and described as the same is only illustrative of the principles of operation, which are capable of extended application'in various forms, and that the invention comprehends all construction within the scope of the claims. f

What I claim is:

l. In an apparatus of the character described,

a pair of conduits arranged at opposite ends of a furnace and including vertical portions, upper and lower horizontal portions and hai/ing the lower horizonal portions arranged in 'a plane below the furnace and having the upper horizontal portions connected to said furnaceA for guiding article carrying boats into and out of said furnace, an endless conveyor operating between said lower horizontal portions of the conduits to receive boats from one of said lower horizontal portions and to deliver boats tov the other lower horizontal portion, means for'moving the boats in the horizontal portion of one of said conduits from its vertical portion to the conveyor, means for moving boats from said conveyor through the lower 'horizontal -portion of the other conduit to the vertical portion thereof, means for moving the boats through the vertical portions of the conduits, means for moving the boats from the upper horizonal portion of one of the conduits into lthe furnace, means for moving boats from the furnace into the uppery horizontal portion of the other conduit.

2. In' an apparatus of the character described. a pair of conduits arranged at opposite ends of a-furnace and including vertical portions, upper and lower horizontal portions and having they lower horizontal portions arranged in a plane below the furnace and having the upper horizontal portions connected to said furnace for guiding article carrying boats into and out of said furnace, an endless conveyor'operating bel tween said lower horizontal portions of the conduits to receive boats from one of said lowerl horizontal portions and to deliver boats to the other lower horizontal portion, means for moving the boats in the horizontal portion of one of said conduits from its 'vertical portion to the conveyor, means for moving boats from said cone veyor -through ,the lower horizontal portion ofducing hydrolgen into said last-named horizontal portion. n.

3. In an apparatus of the character described, a pair of` conduits arranged at oppositg ends of a furnace and including vertical portions, upper and lower horizontal-portions and having the lower horizontal portions arranged in a plane below the furnace and having the upper horizontal portions connected to said furnace for guiding article carrying boats into and out of said furnace, an endless conveyor operating between said lower horizontal portions of the conduits to receive boats from one of said lower horizontal portions and to deliver boats to the other lower horizontal portion, means for moving the boats in the horizontal portion of one ot said con duits from its vertical portion to the conveyor, means for moving the boats,from said conveyor through the lower horlzontalportlon of the `other conduit to the Vertical portion thereof, means formoving the boats through the vertical portions of the conduits, means for moving the boats from the upper horizontal portion of one of the conduits into the furnace, means for moving boats from the furnace into the upper horizontal portion of the other conduit, means for cooling the upper horizontal portion of one of the conduits for cooling articles of the boats while in said lattermamed horizontal portion and after leaving the furnace, means for introducing hydrogen in'to said last-named horizontal portion, gates 'controlling the lower horizontal portions and the vertical portions of the conduits, means for operating the` gates to permit the boats to pass through said conduits, and means for admitting hydrogen into the conduits between said gates.

WOODROW L. WROBLEWSKI. 

